Aformal structure of many art songs that uses the same melody for some verses of poetry while setting other verses to new melodies is called

A formal structure of many art songs that uses the same melody for some verses of poetry while setting other verses to new melodies is called modified Strophic form.
Strophic form is the term applied for the songs in which there is same melody for all verses but when there is same melody for some verses and new melody to other verses, this is called modified Strophic form.